Minor fixes in 1991/cdupont/README.md

Also since it has been requested that the award + author information be
removed from the README.md files this has been done here as these
changes were already done but not committed. Once the remaining (not
counting this one) five other README.md files have been committed there
will be a mass edit.

1991/cdupont/README.md

@@ -1,13 +1,3 @@
-# Most Useful Label
-
-Christian Dupont\
-Ecole Normale Superieure de Lyon\
-Laboratoire d'Informatique Parallele\
-42, Rue H.Berlioz\
-69009 Lyon\
-France
-
-
 ## To build:
 
 ```sh
@@ -40,11 +30,9 @@ this entry.
 
 ## Author's remarks:
 
-Spoiler:
-
 The source code holds the letters of the message. Each letter, combined
 with another key letter, is used to compute the coordinates of the next
-letter and key. Thus, the message is code.  That is why I use silly\
+letter and key. Thus, the message is code.  That is why I use silly
 comments, most often badly spaced.
 
 The space character sequence between the words is given by a simple